Barbarian, Cipher, Priest.
Cipher has huge amounts of control plus some of the best single-target spells in the game. The AOE confuse simply is not replaceable as far as turning the enemies' numbers against them.
Priest has knockdown CC from traps plus much-needed buffs, heals and most importantly, condition immunities. With only 3 members, you CAN NOT afford to have one of them CC'd.
Barb with apprentice sneak attack profits from AOE flanking from phantom foes, and later on can feed the cipher more focus then they can realistically spend with reaping knives.
Weaken (from painful interdiction) and sicken(from barb) are the major affflictions that reduce BOTH fort and will. In POTD you're never going to get fort low enough for brutal, but the will debuff is very nice for the cipher as well as the fort helping the knockdown level 1 power.
Edited by Manty5, 21 April 2018 - 08:19 AM.